HFSC(8) Linux HFSC(8)
NAME
HFSC - Hierarchical Fair Service Curve's control under linux
SYNOPSIS
tc qdisc add ... hfsc [ default CLASSID ]
tc class add ... hfsc [ [ rt SC ] [ ls SC ] | [ sc SC ] ] [ ul SC ]
rt : realtime service curve
ls : linkshare service curve
sc : rt+ls service curve
ul : upperlimit service curve
o at least one of rt, ls or sc must be specified
o ul can only be specified with ls or sc
SC := [ [ m1 BPS ] d SEC ] m2 BPS
m1 : slope of the first segment
d : x-coordinate of intersection
m2 : slope of the second segment
SC := [ [ umax BYTE ] dmax SEC ] rate BPS
umax : maximum unit of work
dmax : maximum delay
rate : rate
For description of BYTE, BPS and SEC - please see UNITS section of
tc(8).
DESCRIPTION (qdisc)
HFSC qdisc has only one optional parameter - default. CLASSID specifies
the minor part of the default classid, where packets not classified by
other means (e.g. u32 filter, CLASSIFY target of iptables) will be
enqueued. If default is not specified, unclassified packets will be
dropped.
DESCRIPTION (class)
HFSC class is used to create a class hierarchy for HFSC scheduler. For
explanation of the algorithm, and the meaning behind rt, ls, sc and ul
service curves - please refer to tc-hfsc(7).
As you can see in SYNOPSIS, service curve (SC) can be specified in two
ways. Either as maximum delay for certain amount of work, or as a band-
width assigned for certain amount of time. Obviously, m1 is simply
umax/dmax.
Both m2 and rate are mandatory. If you omit other parameters, you will
specify linear service curve.
SEE ALSO
tc(8), tc-hfsc(7), tc-stab(8)
Please direct bugreports and patches to: <netdev AT vger.org>
AUTHOR
Manpage created by Michal Soltys (soltys AT ziu.info)
iproute2 31 October 2011 HFSC(8)